The U.S. Congress has given Boeing a break on the implications of legislation passed in 2020 that would have required substantial cockpit changes in new versions of the 737 Max, instead demanding other safety measures to address concerns that arose after two deadly crashes.

The New York Times reports that Boeing said the previous requirement would have been costly to carry out and confusing for pilots trained on other versions of the plane.

But the deal, which was proposed by Senator Maria Cantwell, Democrat of Washington, requires that Boeing make two changes to all Max models that some experts recommended after the 2018 and 2019 crashes that killed a total of 346 people. The manufacturer must now install both an additional system to measure the angle at which the plane meets oncoming air flow — also known as the angle of attack — and a way for pilots to shut off certain distracting stall warnings.